A CLUTCH RELEASE BEARING ASSEMBLY

Abstract: A clutch release assembly for a pull type clutch comprising a diaphragm spring having radially inwardly projecting spring fingers (11), a clutch release bearing (10), a collar (13) secured to the radially inner ends of the spring fingers by a retainer plate (14), and an elastically deformable ring (19) which is engageable with a detent (27) on the release bearing (10) to axially connect the release bearing to the collar in the clutch release direction (A). The assembly also includes a resilient clip (20) which acts between the inner ends of the diaphragm spring fingers (11) and the release bearing (10) to bias the bearing (10) in the clutch release direction (A) and to hold the bearing (10) against the elastically deformable ring (19).

Description: A CLUTCH RELEASE BEARING ASSEMBLY This invention relates to a pull type friction clutch particularly for a motor vehicle. A pull type friction clutch is one in which the clutch release bearing is moved away from the friction clutch driven plate in order to release the clutch. A typical vehicle clutch comprises a clutch driven plate sandwiched between an engine flywheel and a pressure plate. The pressure plate is biased towards the flywheel by a diaphragm spring to clamp the driven plate therebetween. In a pull type clutch, the radially inner ends of the spring fingers are pulled away from the driven plate in order to relieve the clamping load on the driven plate. A clutch release bearing must either be fitted to the inner ends of the spring fingers as in EP-A-044691, or alternatively the release bearing must make a snap fit connection to a retainer mechanism which is in turn fitted to the radially inner ends of the spring fingers. The snap fit connection typically utilises a resilient wire ring as one part of the connecting member such as is disclosed in GB-A-2182111. A problem associated with such connections is that relative movement between the release bearing and the resilient wire ring can cause wear to the wire ring. The present invention seeks to provide a means of reducing wear to the resilient wire ring. Accordingly there is provided a clutch release assembly for a pull type clutch comprising a diaphragm spring having radially inwardly projecting spring fingers, a clutch release bearing, a collar secured to the radially inner ends of the spring fingers by a retainer plate, and an elastically deformable ring which is engagable with a detent on the release bearing to axially connect the release bearing to the collar in the clutch release direction, characterised in that a resilient clip means acts between the inner ends of the diaphragm spring fingers and the release bearing to bias the bearing in the clutch release direction and hold the bearing against the elastically deformable ring. Preferably the resilient clip means is affixed to the radially inner ends of the spring fingers by the retainer plate. Conveniently at least a portion of the elastically deformable ring is mounted on the collar with limited axial play and the resilient clip biases the elastically deformable ring to take up said play in the release direction. The invention will be described by way of example and with reference to the accompanying drawings in which:- Fig 1 is a cross section through a release bearing assembly according to the invention, Fig 2 is a part cross section through the release bearing assembly in Fig 1 during the assembly stage. Fig 3 is a part cross section as in Fig 2, after assembly. In Fig 1 there is shown a clutch release bearing assembly 10 assembled to the radially inner ends of the fingers 11 of a diaphragm spring. The diaphragm spring is a frustoconical spring having an outer continuous annular portion with a plurality of inwardly directed fingers 11. In order to release the clutch the inner ends of the fingers 11 are moved away from the clutch driven plate in the direction of arrow A by a pull operation. A collar 13 is secured to the inner ends of the fingers 11 by a retainer plate 14 located on the other axial side of the spring fingers. The retainer plate 14 has portions that extend through the gaps between the spring fingers to engage the collar 13 and hold the collar 13 on the driven plate side of the spring fingers. The collar 13 has a radial flange 15 with a raised annular rib 16 thereon which acts as a fulcrum for the relative movement of the spring fingers. The collar 13 also has a central substantially cylindrical sleeve 17 which extends axially through to the axially outer side of the spring fingers 11. The sleeve 17 has axially elongated apertures 18 therein which support a elastically deformable ring 19. The ring is preferably made from spring steel wire . The retainer plate 14 also secures a resilient annular clip 20 to the inner ends of the spring f inge rs 11 . The clip 20 projects radially inwardly so that in use the radially inner ends thereof abut the bearing assembly 10. The release bearing assembly 10 has an outer race 21 which is formed integrally with a connecting collar 22 for connection to a clutch actuation means (not shown), and an inner race 23 which has an axially inwardly extending forward portion 24. The axially inner front end portion of the inner race 23 has an outwardly inclined surface 25 thereon with a groove 26 adjacent thereto. An annular shoulder 27 is formed between the groove 26 and the inclined surface 25 and faces axially outwardly. In order to assemble the bearing assembly to the collar 13 the front end of the forward portion 24 pushes axially inwardly against the deformable ring 19 causing the ring 19 to ride up the inclined surface 25. The front end contracts the resilient clip 20 causing it to deflect axially inwardly, and further inwards movement is against the bias of the resilient clip. As the forward portion 24 is moved inwardly the ring 19 passes over the shoulder 27 and into the groove 26. The shoulder 27 forms a detent which is engagable by the ring 19 to axially connect the bearing assembly 10 to the collar 13 in the clutch release direction A. The load in the deflected resilient clip 20 takes out any axial play and holds the shoulder 27 under a pre-load from the spring bias in abutment with the ring 19. The spring bias also moves the ring 19 within the axially elongated apertures 18 so that the ring is held in abutment with the collar 13, to take out any axial play therebetween in the release direction A.

Claims: CLAIMS 1. A clutch release assembly for a pull type clutch comprising a diaphragm spring having radially inwardly projecting spring fingers (11), a clutch release bearing (10), a collar (13) secured to the radially inner ends of the spring fingers by a retainer plate (14), and an elastically deformable ring (19) which is engagable with a detent (27) on the release bearing (10) to axially connect the release bearing to the collar in the clutch release direction (A) , characterised in that a resilient clip means (20) acts between the inner ends of the diaphragm spring fingers (11) and the release bearing (10) to bias the bearing (10) in the clutch release direction (A) and hold the bearing (10) against the elastically deformable ring (19). 2. A release bearing assembly as claimed in Claim 1 characterised in that the resilient clip means (20) is affixed to the radially inner ends of the spring fingers (11) by the retainer plate (14) . 3. A release bearing assembly as claimed in Claim 1 and Claim 2 characterised in that the elastically deformable ring (19) is mounted on the collar (13 ) . 4. A release bearing assembly as claimed in any one of Claim 1 to 3 characterised in that at least a portion of the elastically deformable ring (19) is mounted on the collar (13) with limited axial play (18), and the resilient clip (20) biases the elastically deformable ring (19) to take up said axial play in the release direction (A) . 5. A release bearing assembly as claimed in any one of claims 1 to 4 wherein the resilient clip means (20) acts against the axially inner end (25) of the release bearing assembly. 6. A release bearing assembly as claimed in any one of Claims 1 to 5 characterised in that the detent (27) is a raised annular shoulder adjacent the inner end (25) of the release bearing and the reaction load from the resilient clip means (20) is transferred to the elastically deformable ring (19) through said shoulder (27). 7. A clutch release assembly for a pull type clutch the assembly being constructed and arranged substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

Inventors: CARACINI PIETRO, GALEOTTI DANILO, CARACINI, PIETRO, GALEOTTI, DANILO
Applicants: AUTOMOTIVE PROD ITALIA, CARACINI PIETRO, GALEOTTI DANILO, AUTOMOTIVE PRODUCTS (ITALIA) S.R.L., CARACINI, PIETRO, GALEOTTI, DANILO
Application year: 1994
Main classification: F16D23
IPC codes: F16D23